Genetic testing utility is highest for syndromic supraventricular tachycardia where diagnosis alters prognosis and surveillanceGenetic testing clarifies some heart rhythm issues but is not routine for most cases

BackgroundSupraventricular tachycardias (SVTs) are among the most common arrhythmias encountered in clinical practice and, despite generally low mortality, impose substantial morbidity and healthcare utilization. Clinical heterogeneity in age of onset, recurrence, symptom burden, and overlap with conduction disease or cardiomyopathy suggests underlying biological determinants, including inherited susceptibility. Over the past decade, advances in human genomics have expanded evidence from familial aggregation and rare syndromic disorders to population-scale genome-wide association studies (GWAS), but routine translation into SVT care remains limited.MethodsNarrative review of guideline-based SVT definitions and mechanistic frameworks, familial and rare-variant studies, GWAS/meta-analyses across SVT subtypes (AVNRT, accessory pathway-mediated AVRT/WPW, and focal atrial tachycardia), and translational literature on biomarkers (including microRNA/exosomal biology), functional validation models, and implementation considerations (yield, cost-effectiveness, ethics, and governance)ResultsSVT demonstrates subtype-specific genetic architecture. AVNRT is supported by familial clustering and polygenic/oligogenic susceptibility, with GWAS signals implicating developmental and myocardial structural pathways (e.g., NKX2-5, TTN, MYH6). Accessory pathway-mediated AVRT/WPW shows the clearest genotype-to-substrate relationship, with common and rare variation implicating conduction and junctional developmental biology (including SCN5A/SCN10A- and CCDC141-linked signals, and emerging family-based discoveries such as MRC2). In contrast, the genetic basis of focal atrial tachycardia remains underpowered and mechanistically heterogeneous. The highest current clinical utility of genetics lies in identifying syndromic and cardiomyopathy-associated SVT (e.g., PRKAG2, LAMP2), where diagnosis alters prognosis, surveillance, and cascade screening.ConclusionGenetic discoveries are reshaping SVT from a purely “functional” arrhythmia toward a spectrum of inherited electrophysiologic and myocardial disease. While routine genetic testing is not indicated for most isolated SVT, phenotype-guided evaluation, improved functional models, and implementation frameworks may enable targeted, patient-centred personalization particularly in early-onset, familial, or cardiomyopathy-overlap presentations.